Detection of a Cephalosporin C Acetyl Esterase in the Carbamate Cephalosporin Antibiotic-Producing Culture, Streptomyces clavuligerus

Abstract

The possible role of a cephalosporin C acetyl esterase in the formation of the β-lactam antibiotic A16886A, 7-(5-amino-5-carboxyvaleramido)-3-carbamoyloxy-methyl-3-cephem-4-carboxylic acid, by Streptomyces clavuligerus was studied. Addition of dl -valine- 14 C-1 to a fermentation of Cephalosporium acremonium gave cephalosporin C- 14 C-9 (I). The formation of deacetylcephalosporin C- 14 C-9 from I occurred at a greater rate in broths of S. clavuligerus than in the broths of C. acremonium , or in the autoclaved broths of S. clavuligerus . Diisopropylfluorophosphate partially inhibited the deacetylation of I in S. clavuligerus broth. An intracellular cephalosporin C esterase in S. clavuligerus could not be demonstrated. Although A16886A has been chemically synthesized from deacetylcephalosporin C, this reaction could not be demonstrated with S. clavuligerus .